1. Technical Field
The present invention relates to an audio processing method and apparatus.
2. Description of Related Art
As computer technology develops, digital multimedia technology and related applications are widely utilized in our daily lives and social activities. Most multimedia files (for example, video, audio, pictures, etc.) need to be converted for transmission through limited network bandwidth. As for audio compression standards, MPEG-1 Layer 3 (MP3) is the most popular. As technology develops, many new audio standards with higher compression ratios and better compression quality are being developed. In 1994, the Moving Picture Experts Group (MPEG) announced a new audio compression standard, namely, MPEG-2 Advanced Audio Coding (AAC). Since MPEG-2 AAC has better compression efficiency and quality than MP3, it is believed that MP3 will be replaced by MPEG-2 AAC. In addition, MPEG-4 AAC, which utilizes MPEG-2 AAC as its kernel, was subsequently announced in 1998. MPEG-4 AAC adopts many advanced technologies to solve issues related to compression efficiency and quality, and is expected to be popular in the future.
In the prior art, fast Fourier transform (FFT), the computing complexity of which is very high, is used in the Psychoacoustic Model (PAM) of MPEG-2/4 AAC. As a result, it is hard for mobile apparatuses (for example, mobile phones, portable audio players, USB flash drives, etc.) to play audio utilizing MPEG-2/4 AAC in real time due to its high complexity.
Hence, there is a need to reduce the computing complexity of audio compression while maintaining good audio quality.